Polar-bulge galaxies

TL;DR

This study identifies and analyzes nine edge-on spiral galaxies with polar bulges using SDSS data, revealing their morphological similarities to late-type spirals and normal bulges, with common disk warps likely caused by external interactions.

Contribution

First detailed photometric analysis of polar-bulge galaxies, characterizing their bulges and disks and comparing them to typical spiral galaxy components.

Findings

Disks are typical for late-type spiral galaxies.

Bulges have parameters similar to normal bulges.

Large-scale warps in disks suggest external interactions.

Abstract

Based on SDSS data, we have selected a sample of nine edge-on spiral galaxies with bulges whose major axes show a high inclination to the disk plane. Such objects are called polar-bulge galaxies. They are similar in their morphology to polar-ring galaxies, but the central objects in them have small size and low luminosity. We have performed a photometric analysis of the galaxies in the g and r bands and determined the main characteristics of their bulges and disks. We show that the disks of such galaxies are typical for the disks of spiral galaxies of late morphological types. The integrated characteristics of their bulges are similar to the parameters of normal bulges. The stellar disks of polar-bulge galaxies often show large-scale warps, which can be explained by their interaction with neighboring galaxies or external accretion from outside.